This invention relates to new and useful improvements in machines for measuring the belt forces and the maximum torque load capacity in the power transmission drive of the flat belt, and the like.
Flat belts are used wherein motion or power is transmitted from one pulley to another. Power transmission capacity depends on the torque load transmitted and the belt speed. The amount of torque load transmitted is proportional to the summation of friction forces between the belt and pulley. The friction force between the belt and pulley depends on the normal pressure and a coefficient of friction.
The coefficient of friction for the flat belt drive is normally obtained from a belt-pulley experiment and Euler's formula. In applying Euler's formula, the experiment data for tight side belt tension, slack side belt tension and the arc of contact are required. In this kind of experiment, the change in belt forces versus angular position along the contact arc cannot be included. The coefficient of friction obtained from these experimental data is constant. However, in reality, the coefficient of friction varies depending on normal pressure and the rate of slip.
Measuring the distribution of normal and tangential belt forces versus angular position in the arc of contact can give a more accurate coefficient of friction as a function of belt normal pressure because belt force distribution is directly related with friction characteristics; i.e., coefficient of friction. The accurate friction characteristics obtained can be used to determine the optimal belt tension and to improve the power transmission efficiency.
The present invention is directed to new force transducers and apparatus for measuring the normal and tangential belt forces versus angular position in the arc of contact for the flat belt drive.